To improve the spraying characteristics of pressurized aerosol dispensers, various nozzle design ideas have been employed. Valve actuators or buttons have been provided with a swirl chamber having a tangential entrance to cause a spin of the product stream before it issues from the discharge orifice. That spin causes the stream to break into relatively small droplets in response to centrifugal force as the product stream issues from the discharge orifice. This mechanical break-up of the product stream provides an excellent spray pattern in terms of evenness of droplet distribution and of droplet size. Abplanalp et al., U.S. Pat. Nos. 2,989,251, 3,008,354, 3,083,917, and 3,083,918 show various mechanical break-up buttons and the dies for injection molding them.
Actuators according to the present invention produce spray characteristics superior to prior mechanical break-up actuators. Further, it has been found that the need to make adjustments to the dies to produce actuators having uniform excellent spray patterns can be reduced by incorporating the modifications which are the subject of the present invention. The resulting actuators are more uniform in their spray characteristics over a long molding run on a set of dies.